1. Field of the Invention
The present invention relates to swimming goggles, and particularly to swimming goggles having buckles operated by pressing upper and lower portions thereof to quickly and easily adjust the length of a head strap without snapping a wearer's hair.
2. Related Art
In general, swimming goggles are provided with buckles disposed on left and right sides of frames for connecting a head strap, which is allowed to be adjustable in length through the buckles. Each of the buckles includes an engaging arm for engaging serrated grooves of the head strap. When the engaging arm engages the head strap, the head strap merely can be tightened in a single direction. To loosen the head strap, the engaging arm has to be disengaged with the serrated groove. As a result, adjustment of the head strap is directly associated with engagement of the engaging arm and the serrated groove.
Traditional buckles, which controls engagement of the engaging arm, is commonly designed based on a first lever principle, that is, to exert pressing force on one end of the engaging arm, while the opposite end of the engaging arm moves in a reverse direction to release the engaging arm. Furthermore, a resilient element is provided on the end of the engaging arm where pressing force applied thereon for returning the engaging arm.
However, pressing elements used to press the engaging arms of traditional buckles are disposed at a side of the buckles directly contacting a wearer's head and therefore are easily to snap the wearer's hair. Furthermore, a traditional engaging arm must operate with an additional element, the resilient element, to help the engaging arm return to a previous state. Consequently, traditional buckles have complex structure which leads to a high manufacturing cost and are difficult for assembly.